Log some svnserve errors (I'm sure we have a lot more we could log).

Log some svnserve errors (I'm sure we have a lot more we could log).

* subversion/svnserve/serve.c
  (log_write): Add simple wrapper around svn_io_file_write().
  (log_error):
    - Move most of the old log_fs_warning logic to this new function,
      which takes err, log_file, remote_host, user, and repos
      directly, so it can be used from main(), too.
    - Do nothing if err is NULL
    - Log NULL repos as "-"
    - Expand format to include the err debug info (file/line) when available.
    - Use log_write().
  (log_server_error): Add wrapper around log_error that gets most of
    the arguments from server_baton_t and svn_ra_svn_conn_t
  (error_create_and_log): Add helper function to create, log, and
    return a new error.
  (log_command): Rename from svnserve_log.  Use log_write.
  (SLOG, replay_one_revision): Use log_command.
  (load_configs): Take server_baton_t and svn_ra_svn_conn_t arguments
    in order to log errors when called from serve().  main() passes
    NULL for them, in which case this still returns them, and main()
    still exits non-zero.  Return generic errors to the user instead
    of leaking the passwd/authz file paths, but log the full error
    (fixes svn issue 2271).  Move below log functions.
  (lookup_access): Take svn_ra_svn_conn_t argument and use it to log
    authz_check_access errors before discarding (fixing an old TODO).
  (must_have_access, add_lock_tokens, lock_many, unlock_many): Pass
    conn along to lookup_access.  Log the access denied error we
    return to the user.
  (unlock_paths): Take new conn argument to use in logging errors from
    svn_repos_fs_unlock before discarding (fixing an old TODO).
  (commit): Pass conn along to unlock_paths.
  (find_repos): Take new conn argument to pass along to load_configs.
    Log the access denied error we return to the user.
  (fs_warning_func): Renamed from log_fs_warning and now just a simple
    wrapper around log_server_error.
  (serve): Log the access denied error we return to the user.  Log
    errors from find_repos.

* subversion/svnserve/server.h
  (load_configs): Update declaration.
  (log_error): Declare.

* subversion/svnserve/main.c
  (main): Log errors from serve before discarding.  Log fork(2) errors.

* subversion/tests/cmdline/authz_tests.py
  (authz_validate): Adapt svnserve error messages.

git-svn-id: http://svn.collab.net/repos/svn/trunk@30827 612f8ebc-c883-4be0-9ee0-a4e9ef946e3a